Product Description
Suitable for: boiler, chain furnace, circulating fluidized bed, rotary kiln, etc.
SNCR and SCR are commonly used in flue gas denitrification. Compared with SNCR and SCR, SNCR has the following characteristics.
First, the biggest difference between SNCR and SCR is that no catalyst is used in the denitrification process, and it does not lead to oxidation of SO:/SOa, SO the chance of clogging the air preheater is very small.
Second, there is no pressure loss in the whole process, so there is no need to improve the pressure head of the induced draft fan, especially the transformation of the unit does not need to transform the induced draft fan, which saves investment and shortens the construction period.
Third, the equipment required by SNCR occupies a small area, and compared with SCR equipment, it is simple, the construction amount is reduced, and the project implementation time is shortened. For the transformation unit, it is more convenient for the project implementation under the condition of large site restrictions.
Fourth, the whole reduction process of SNCR process is carried out in the boiler, and there is no need to set up another reactor.
The reducing agent is injected into the flue gas through a nozzle mounted on the wall of the boiler.
The nozzles are arranged in the superheater area between the combustion chamber and the economizer. The heat of the boiler provides energy for the reaction, so that NOx is reduced here.
The cancellation of the reactor, the supporting steel structure of the reactor and its auxiliary flue reduces a large part of the investment, reduces most of the installation work, and is more convenient for future overhaul and maintenance work.
System principle
The treatment stages of nitrogen oxides in flue gas are generally divided into early fuel treatment, combustion process control and late flue gas denitrification.Fuel pretreatment is to remove nitrogen from fuel, no industrial application;Combustion process control is mainly to improve the combustion state, control excess air, reduce combustion temperature, etc.The late flue gas denitrification technology is mainly selective non-catalytic reduction reaction technology, selective catalytic reduction reaction technology and combined denitrification technology and the development of integrated denitrification technology.In addition, there are microbial method, electron beam method, activated carbon adsorption method and other technologies, but they have not been applied and promoted in engineering because of the operation cost, operation difficulty and other reasons.The most mature and widely used SCR denitration technology is recommended for the best technical route of gas heating furnace.
heating furnace is about 200℃.Considering that the flue gas volume of this project is small and the sulfur content of flue gas is high, in order to ensure the denitration efficiency and reduce the project cost.This project plans to equip a set of hot blast stove flue gas heating device, heating the original flue gas from 200℃ to 320℃.
Set up a SCR denitration reaction device, a set of reducing agent storage, pyrolysis, uniform distribution system.The flue gas enters the denitrification temperature before 320℃, after spraying ammonia, rectifier grid into the SCR catalyst module, complete the NOx reduction process, NOx is reduced to non-toxic and harmless N2 into the atmosphere;The flue gas after denitration enters the desulfurization tower through induced draft fan for subsequent desulfurization and dust removal treatment.
